This invention relates to a fixture for a milling machine. In particular, the invention relates to a chip guard and the milling machine equipped with the chip guard.
It is considered good practice to shield machine operators from workplace hazards. The Occupational Safety & Health Administration (OSHA) of the U.S. Department of Labor, in Standard No. 1910.22, requires that one or more methods of machine guarding be provided to protect operators from hazards associated with machine tool operation. For these reasons, a variety of guard designs have been developed. The background art is characterized by the inventions described in U.S. Pat. Nos. 1,527,998; 1,563,887; 3,703,124; 3,837,383; 4,043,701; 4,126,081; 4,132,497; 4,162,647; 4,290,717; 4,543,012; 4,543,021; 4,552,494; 4,884,927; 5,103,541; 5,218,887; and 5,479,837; the disclosures of which patents are incorporated herein as if fully set forth.
Serpico in U.S. Pat. No. 1,527,998 discloses a protective guard for a router. This invention is limited in that it must be attached to the router rod portion of the router. The invention is further limited in that the glass guard can only be pivoted about a horizontal axis.
Wiespetat in U.S. Pat. No. 1,563,887 discloses a drill press guard. This invention is limited in that the guard must be attached to the feed rack or quill of the drill press.
Smith et al. in U.S. Pat. No. 3,703,124 disclose a machine tool guard and/or safety guard. This invention is limited in that it is attached to a slot in the table of the machine tool and does not effectively protect the user when the tool is raised above the surface of the table.
Ko in U.S. Pat. No. 3,837,383 discloses a dust collector and safety guard. This invention is limited in that it is attached to the machine tool by means of a flange that must be fixed to the machine.
Jaeger in U.S. Pat. No. 4,043,701 discloses a safety shield assembly. This invention is limited in that it is attached to the machine tool by means of a bracket.
Zdeb in U.S. Pat. No. 4,126,081 discloses a safety shield for a machine tool. This invention is limited in that the safety shield must be attached to the quill of the milling machine. The invention is further limited in that the panels of the shield can only be pivoted about a horizontal axis.
Weller et al. in U.S. Pat. No. 4,132,497 disclose drilling machines and guards therefor. This invention is limited in that it must be attached to the quill of a vertical milling machine.
Aslen in U.S. Pat. No. 4,162,647 discloses a guard for a milling machine that comprises a combination of rods and blocks supporting guard panels relative to the milling tool. In one embodiment, the invention of Aslen comprises a plurality of mounting bars that are attached to the dovetail of a milling machine ram by means of clamping blocks secured in place with clamping bolts. Each mounting bar supports a pair of mounting blocks from which support rods extend into support blocks. A mounting rod extends downward from each support block to which an attachment block is secured. Each pair of support blocks a guard panel. This invention is limited in that multiple mounting bars, mounting blocks, support blocks and attachment blocks are required. The requirement for multiple mounting bars and blocks means that the device cannot be attached to the end of the dovetail when the ram is moved backward leaving only a short portion of the dovetail forward of the turret, which is normally the case. The invention is further limited in that planar guard panels are provided, which panels can only be pivoted about a horizontal axis.
Aslen in U.S. Pat. No. 4,290,717 discloses machinery safety guards. This invention is limited in that it must be attached to the barrel of a vertical milling machine.
Adler in U.S. Pat. No. 4,543,021 discloses a safety shield for a machine tool. This invention is limited in that it must be connected by a series of rods, links, knuckle joints, etc. to an existing hole in a Bridgeport type milling machine.
Wix in U.S. Pat. No. 4,552,494 discloses a collapsible safety shield for a vertical drill press. This invention is limited in that it must be attached to the drill housing.
Menker in U.S. Pat. No. 4,884,927 discloses a shield unit for a machine tool. This invention is limited in that it must be attached to the machine tool's spindle adjustment rod.
Ferletic in U.S. Pat. No. 5,103,541 discloses a milling machine stop bar for use with reversing tapping attachments. The stop-bar is clamped onto the ram of the milling machine. This invention is limited in that it does not provide a guard for protection of the machine operator.
Ziobro in U.S. Pat. No. 5,218,887 discloses a drill chuck and revolving spindle guard. This invention is limited in that the safety shield must be attached to the quill of milling machine. The invention is further limited in that the guard cannot be repositioned vertically.
Kyle in U.S. Pat. No. 5,479,837 discloses a guard for a channel bed press. This invention is limited in that it attaches to the rear channel on the channel bed of such a press.
The inventions in the related art exhibit one or more limitations. Many related art milling machine guards attach to the quill, quill housing, barrel, etc. of the machine, parts which are tilted from the vertical or moved relative to the workpiece during some machine operations. Under these conditions, the related art guards can interfere with the operations and the guards can be rendered less effective by their orientation or distance from the workpiece. The related art fixtures that attach to the dovetail of the milling machine ram are overly mechanically complex and, hence, expensive to manufacture and difficult to use, not designed to be attached to the end of the dovetail or fail to guard the operator. None of the related art fixtures can be moved out of the way when not required. Furthermore, none of the related art fixtures direct oil to the cutting face.